Is a rats ecosystem built or natural?

A rat's ecosystem can be considered both built and natural. In urban environments, rats often thrive in man-made structures like buildings, sewers, and waste areas, which provide abundant food and shelter. However, in rural or wild settings, they inhabit natural ecosystems, such as forests or grasslands, where they play a role in the local food chain. Thus, their ecosystem is a blend of human influence and natural habitats.